Semiconductor device and method of manufacturing the same

ABSTRACT

A semiconductor device includes a substrate having an active pattern, a conductive pattern crossing the active pattern, a spacer structure on at least one side surface of the conductive pattern, and a capping structure on the conductive pattern. The capping structure includes a first capping pattern and a second capping pattern. The second capping pattern is disposed on a top surface of the first capping pattern and a top surface of the spacer structure.

PRIORITY STATEMENT

This application claims priority under 35 U.S.C. § 119 to Korean PatentApplication No. 10-2016-0052146 filed on Apr. 28, 2016 in the KoreanIntellectual Property Office, the disclosure of which is herebyincorporated by reference in its entirety.

BACKGROUND

1. Field

The inventive concept relates to a semiconductor device and to a methodof manufacturing the same. More specifically, the inventive conceptrelates to the gate structure of a field effect transistor and to amethod of manufacturing the same.

2. Description of the Related Art

Semiconductor devices owing to high performance, small size and/or lowmanufacturing cost characteristics have been used as essential devicesin the electronics industry. The semiconductor devices are classifiedinto semiconductor memory devices for storing logical data,semiconductor logic devices for processing the logical data and hybridsemiconductor devices including a memory element and a logic element. Asthe electronics industry has been highly developed, a demand forsemiconductor devices of high speed, high reliability and multifunctionhas increased. To meet these characteristics, semiconductor devices havebecome highly integrated and internal structures of semiconductordevices have become highly complex.

SUMMARY

According to the inventive concept, there is provided a semiconductordevice including a substrate having an active pattern, a conductivepattern crossing the active pattern, a respective spacer structure oneach of at least one of the side surfaces of the conductive pattern, thespacer structure having a top surface, and a capping structure on theconductive pattern, and in which the capping structure includes a firstcapping pattern, the first capping pattern having a top surface, and asecond capping pattern, and the second capping pattern is disposed onthe top surface of the first capping pattern and on the top surface ofthe spacer structure.

According to the inventive concept, there is also provided asemiconductor device including a substrate having an active pattern, aconductive pattern crossing the active pattern, and a capping structureon the conductive pattern, and in which the capping structure includes afirst capping pattern and a second capping pattern on the first cappingpattern, the first capping pattern has an indentation, the secondcapping pattern has a protrusion received in the indentation as engagedwith the first capping pattern, and a width of the second cappingpattern is greater than a width of the first capping pattern.

According to the inventive concept, there is also provided a method ofmanufacturing a semiconductor device, including forming a conductivepattern crossing an active pattern on a substrate, forming spacer layerson opposite side surfaces of the conductive pattern, forming a firstcapping layer on the conductive pattern and the spacer layers, recessingthe first capping layer and the spacer layers, within insulatingmaterial, to form a first capping pattern and spacer structures, andforming a second capping pattern on a top surface of the first cappingpattern and top surfaces of the spacer structures.

According to the inventive concept, there is also provided asemiconductor device, including a substrate having an active patternincluding a source/drain (S/D) region, an interlayer dielectric layer onthe substrate, at least one conductive pattern extending longitudinallyin a first direction across the active pattern within the interlayerdielectric layer, a respective spacer structure on each of at least oneof the side surfaces of the conductive pattern, a capping structure onthe conductive pattern, and a contact structure extending vertically inthe interlayer dielectric layer to the S/D region, and in which thecontact structure comprises a conductive member electrically connectedto the S/D region, the capping structure includes a first cappingpattern and a second capping pattern having a first portion disposed onthe top surface of the first capping pattern and a second portion on thetop surface of the spacer structure, the contact structure is disposedagainst the spacer structure and the second portion of the secondcapping pattern, and the second capping pattern is of material having anetch selectivity with respect to that of the interlayer dielectriclayer.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view illustrating a semiconductor deviceaccording to an example of the inventive concept.

FIG. 2 is a cross-sectional view taken along line A-A′ of FIG. 1.

FIG. 3 is a plan view illustrating a semiconductor device according toan example of the inventive concept.

FIGS. 4A, 4B and 4C are cross-sectional views taken along lines A-A′,B-B′ and C-C′ of FIG. 3, respectively.

FIG. 5 is an enlarged cross-sectional view of region “M” of FIG. 4A.

FIGS. 6A, 6B and 6C are enlarged cross-sectional views of region “N” ofFIG. 4A.

FIGS. 7, 9, 11, 13, 15, 17, 19, 21, 23 and 25 are plan viewsillustrating a method of manufacturing a semiconductor device accordingto an example of the inventive concept.

FIGS. 8A, 10A, 12A, 14A, 16A, 18A, 20A, 22A, 24A and 26A arecross-sectional views taken along lines A-A′ of FIGS. 7, 9, 11, 13, 15,17, 19, 21, 23 and 25, respectively, FIGS. 8B, 10B, 12B, 14B, 16B, 18B,20B, 22B, 24B and 26B are cross-sectional views taken along lines B-B′of FIGS. 7, 9, 11, 13, 15, 17, 19, 21, 23 and 25, respectively, andFIGS. 10C, 12C, 14C, 16C, 18C, 20C, 22C, 24C and 26C are cross-sectionalviews taken along lines C-C′ of FIGS. 9, 11, 13, 15, 17, 19, 21, 23 and25, respectively.

FIG. 27 is a plan view illustrating a semiconductor device according toan example of the inventive concept.

FIGS. 28A and 28B are cross-sectional views taken along lines A-A′ andB-B′ of FIG. 27, respectively.

FIG. 29 is a plan view illustrating a semiconductor device according toan example of the inventive concept.

FIGS. 30A and 30B are cross-sectional views taken along lines A-A′ andB-B′ of FIG. 29, respectively.

DETAILED DESCRIPTION

Various examples of the inventive concept will now be described morefully with reference to the accompanying drawings. However, theinventive concept may be embodied in many alternate forms and should notbe construed as limited to only the examples described hereinafter.

FIG. 1 is a perspective view illustrating a semiconductor deviceaccording to an example of the inventive concept. FIG. 2 is across-sectional view taken along line A-A′ of FIG. 1.

Referring to FIGS. 1 and 2, a substrate 100 having an active pattern APmay be provided. The substrate 100 may be, for example, a siliconsubstrate, a germanium substrate, or a silicon-on-insulator (SOI)substrate. The active pattern AP may be disposed on the substrate 100.The active pattern AP may upwardly protrude from the substrate 100. Theactive pattern AP may include a pair of source/drain regions SD and achannel region CH between the pair of source/drain regions SD. Thesource/drain regions SD may be impurity regions that are doped withimpurities having a different conductivity type from the substrate 100.

A conductive pattern may be disposed on the channel region CH. As anexample, the conductive pattern may include a gate electrode GE crossingthe active pattern AP. The gate electrode GE may have a linear shapethat extends in a first direction D1 parallel to a top surface of thesubstrate 100. The gate electrode GE may include a doped semiconductormaterial (e.g., doped silicon, doped germanium, etc.), a conductivemetal nitride (e.g., titanium nitride, tantalum nitride, etc.) and/or ametal (e.g., aluminum, tungsten, etc.)

Spacer structures GS may be respectively disposed on opposite sidewallsof the gate electrode GE. The spacer structures GS may extend in thefirst direction D1 along the gate electrode GE. Top surfaces GSt of thespacer structures GS may be higher than a top surface GEt of the gateelectrode GE. The spacer structures GS may each include a plurality ofspacers SP1, SP2 and SP3. In other words, the plurality of spacers SP1,SP2 and SP3 may be multiple layers that are sequentially stacked on asidewall of the gate electrode GE. The plurality of spacers SP1, SP2,and SP3 may include a first spacer SP1, a second spacer SP2 and a thirdspacer SP3.

Bottom surfaces of the first through third spacers SP1, SP2 and SP3 maybe substantially coplanar with each other and top surfaces of the firstthrough third spacers SP1, SP2 and SP3 may be substantially coplanarwith each other. The second spacer SP2 may be interposed between thefirst spacer SP1 and the second spacer SP2. A dielectric constant of thesecond spacer SP2 may be lower than that of the first and third spacersSP1 and SP3. The second spacer SP2 may have a width greater than that ofeach of the first and third spacers SP1 and SP3. In other words, thepercentage of the second spacer SP2 by volume in the spacer structure GSmay be greater than that of each of the first and third spacers SP1 andSP3 in the spacer structure GS. Because the dielectric constant of thesecond spacer SP2 is relatively low, the spacer structure GS having arelatively low dielectric constant may be formed.

The first through third spacers SP1, SP2 and SP3 may each include atleast one of SiO₂, SiCN, SiCON and SiN. In some examples, the secondspacer SP2 may contain more oxygen than the first through third spacersso as to have the relatively low dielectric constant. In other words, aconcentration of oxygen atoms in the second spacer SP2 may be greaterthan that in each of the first and third spacers SP1 and SP3. As anexample, the first and third spacers SP1 and SP3 may include SiN and thesecond spacer SP2 may include SiCON.

A gate dielectric pattern G1 may be disposed between the gate electrodeGE and the channel region CH and between the gate electrode and the pairof spacer structures GS. The gate dielectric pattern GI may extend inthe first direction D1. The gate dielectric pattern GI may include apair of extension portions GIe. The extension portions GIe may eachextend in a third direction D3 along inner sidewalls of the spacerstructure GS. The third direction D3 may be a direction perpendicular tothe top surface of the substrate 100. Top surfaces of the extensionportions GIe may be substantially coplanar with the top surfaces GSt ofthe spacer structure GS. In other words, the top surfaces of theextension portions GIe may be higher than the top surface GEt of thegate electrode GE.

The gate dielectric pattern GI may include at least one of siliconoxide, silicon nitride and a high-k dielectric material having adielectric constant greater than that of silicon oxide. The high-kdielectric material may include, for example, at least one of hafniumoxide, hafnium silicon oxide, lanthanum oxide, zirconium oxide,zirconium silicon oxide, tantalum oxide, titanium oxide, bariumstrontium titanium oxide, barium titanium oxide, strontium titaniumoxide, lithium oxide, aluminum oxide, lead scandium tantalum oxide andlead zinc niobate.

The gate electrode GE may be recessed, i.e., its top surface GEt may belower than the top surface GSt of the spacer structure GS and a topsurface of the gate dielectric pattern GI. Thus, a first recess regionRC1 may be defined on the gate electrode GE. Specifically, the firstrecess region RC1 may include a recess defined by inner sidewalls of theextension portions GIe and the top surface GEt of the gate electrode GE.

A capping structure GP may be disposed on the gate electrode GE. Thecapping gate structure GP may extend in the first direction D1 along thegate electrode GE. As an example, the cross section of the cappingstructure GP, in a second direction D2 crossing the first direction D1,may have a T-shape (refer to FIG. 2). The capping structure GP mayinclude a first capping pattern CP1 and a second capping pattern CP2that are sequentially stacked.

The first capping pattern CP1 may be disposed on the top surface GEt ofthe gate electrode GE. The first capping pattern CP1 may be interposedbetween the gate electrode GE and the second capping pattern CP2. Inaddition, the first capping pattern CP1 may be interposed between thespacer structures GS. The first capping pattern CP1 may be disposed inthe first recess region RC1. In other words, the first capping patternCP1 may be surrounded by the gate electrode GE, the second cappingpattern CP2 and the pair of spacer structures GS. At least a portion ofa top surface CP1 t of the first capping pattern CP1 may besubstantially coplanar with the top surfaces GSt of the spacerstructures GS. In other words, at least a portion of the top surface CP1t of the first capping pattern CP1 may be positioned at substantiallythe same level as the top surfaces GSt of the spacer structures GS.

The first capping pattern CP1 may have a width W1 in the seconddirection D2. For example, the width W1 of the first capping pattern CP1may be substantially equal to the width of the gate electrode GE in thesecond direction.

The first capping pattern CP1 may include an indentation DE formed in atop surface thereof. The indentation DE may be in the form of a groovethat extends longitudinally in the first direction D1. The indentationDE may have a width W3 in the second direction D2. The width W3 may beless than the width W1 of the first capping pattern CP1.

The second capping pattern CP2 may be disposed on the top surface CP1 tof the first capping pattern CP1 and the top surfaces GSt1 of the spacerstructure GS. In other words, the second capping pattern CP2 may coverthe entire top surface CP1 t of the first capping pattern CP1 and theentire top surfaces GSt1 of the spacer structure GS. The second cappingpattern CP2 may extend from the top surface CP1 t of the first cappingpattern CP1 to the top surfaces GSt of the spacer structures GS.Opposite sidewalls of the second capping pattern CP2 may each be alignedwith a sidewall of each spacer structure GS. The sidewall of each spacerstructure GS may be a sidewall of the third spacer SP3. The oppositesidewalls of the second capping pattern CP2 and the sidewall of eachspacer structure GS may be covered by an interlayer insulating layer130. A top surface CP2 t of the second capping pattern CP may besubstantially coplanar with a top surface of the first interlayerinsulating layer 130 covering the substrate 100.

The second capping pattern CP2 may have a width W2 in the seconddirection D2. The width W2 of the second capping pattern CP2 may begreater than the width W1 of the first capping pattern CP1.

The second capping pattern CP2 may include a protrusion portion PP (orsimply “protrusion”) projecting toward the substrate 100 at a bottomsurface thereof. The protrusion portion PP may have a linear shape thatextends in the first direction D1. The protrusion portion PP may becomplementary to and received in the indentation DE.

The second capping pattern CP2 may include a material having an etchingselectivity with respect to the first interlayer insulating layer 130.For example, in a dry etching process using fluorocarbon (C_(x)F_(y)) asan etching gas, the second capping pattern CP2 may include a materialhaving an etching selectivity with respect to the first interlayerinsulating layer 130. In some examples, in the case where the firstinterlayer insulating layer 130 may include silicon oxide, the secondcapping pattern CP2 may include at least one of SiON, SiCN, SiCON, SiNand Al₂O₃.

In some examples, the first capping pattern CP1 may include the samematerial as the second capping pattern CP2. In other examples, the firstcapping pattern CP1 may include a different material from the secondcapping pattern CP2. In this case, a dielectric constant of the secondcapping pattern CP2 may be greater than that of the first cappingpattern CP1. In the case of a material having a relatively highdielectric constant in general, an etching selectivity of the materialwith respect to silicon oxide forming the first interlayer insulatinglayer 130 may be higher. The first capping pattern CP1 may include atleast one of SiON, SiCN, SiCON, SiN and Al₂O₃. As an example, the firstand second capping patterns CP1 and CP2 may include SiN. As anotherexample, the first capping pattern CP1 may include SiON, and the secondcapping pattern CP2 may include SiN. As still another example, the firstcapping pattern CP1 may include SiN, and the second capping pattern CP2may include Al₂O₃.

FIG. 3 is a plan view illustrating a semiconductor device according toan example of the inventive concept. FIGS. 4A, 4B and 4C arecross-sectional views taken along lines A-A′, B-B′ and C-C′ of FIG. 3,respectively. FIG. 5 is an enlarged cross-sectional view of region “M”of FIG. 4A. FIGS. 6A, 6B and 6C are enlarged cross-sectional views ofregion “N” of FIG. 4A. Hereinafter, the same elements as described withreference to FIGS. 1 and 2 will not be described again or will only bementioned briefly for the sake of brevity.

Referring to FIGS. 3, 4A through 4C, 5 and 6A, a substrate 100 may beprovided. For example, the substrate 100 may be a silicon substrate, agermanium substrate or a silicon-on-insulator (SOI) substrate. A firsttransistor TR1 and a second transistor TR2 may be disposed on thesubstrate 100. The first and second transistors TR1 and TR2 may beprovided on a region of the substrate 100.

In some examples, the region of the substrate 100 may be a memory cellregion in which a plurality of memory cells for storing data aredisposed. As an example, memory cell transistors configuring a pluralityof SRAM cells may be disposed in the memory cell region of the substrate100. The first and second transistors TR1 and TR2 may constitute two ofthe memory cell transistors, i.e., may be representative of the memorycell transistors.

In other examples, the region of the substrate 100 may be a logic cellregion in which logic transistors configuring logic circuits of thesemiconductor device are disposed. As an example, the logic transistorsconfiguring a processor core or I/O terminals may be disposed in thelogic cell region. The first and second transistors TR1 and TR2 mayconstitute two of the logic transistors, i.e., may be representative ofthe logic transistors. However, aspects of the inventive concept are notlimited thereto.

The first and second transistors TR1 and TR2 may be transistors ofdifferent conductive types. For example, the first transistor TR1 may bea PMOSFET, and the second transistor TR2 may be an NMOSFET.

The substrate 100 may include a first active pattern AP1 and a secondactive pattern AP2 at the top thereof. The first active pattern AP1 maybe an active pattern for the first transistor TR1, and the second activepattern AP2 may be an active pattern for the second transistor TR2.

The first and second transistors AP1 and AP2 may extend parallel to eachother in the second direction D2. The first and second transistors AP1and AP2 may be spaced apart from each other with a second deviceisolation pattern ST2 therebetween. First device isolation patterns ST1may be disposed on opposite sides of the first active pattern AP1 andmay define the first active pattern AP1. Also, the first deviceisolation patterns ST1 may be disposed on opposite sides of the secondactive pattern AP1 and may define the second active pattern AP2.

Although not shown, the first active pattern AP1 may include a pluralityof first active regions adjacent to each other, and the second activepattern AP2 may include a plurality of second active regions adjacent toeach other. In this case, the first device isolation patterns ST1 may beinterposed between the adjacent first active regions and between theadjacent second active regions.

The first and second device isolation patterns ST1 and ST2 may beinsulating layers connected to each other so as to be a substantiallyintegral structure of insulating material. The second device isolationpattern ST2 may have a thickness greater than that of the first deviceisolation pattern ST1. In this case, the first device isolation patternST1 may be formed by a process separate from a process of forming thesecond device isolation pattern ST2. In some examples, the first andsecond device isolation patterns ST1 and ST2 may be concurrently formedand have substantially the same thickness. The first and second deviceisolation patterns ST1 and ST2 may be formed in the upper portion of thesubstrate 100. For example, the first and second device isolationpatterns ST1 and ST2 may be constituted by a silicon oxide layer.

Gate electrodes GE may be disposed on and cross the first and secondactive patterns AP1 and AP2. The gate electrodes GE may extend in thefirst direction D1 to traverse the first and second device isolationpatterns ST1 and ST2. The gate electrodes GE may be spaced apart fromeach other in the second direction D2.

Interfacial layers IL may be respectively interposed between the firstand second active patterns AP1 and AP2 and the gate electrodes GE. Theinterfacial layers IL may respectively cover upper portions of the firstand second active patterns AP1 and AP2 (e.g., top surfaces and sidewallsof channel regions CH that will be described later). The interfaciallayers IL may include a silicon oxide layer.

Referring again to FIG. 6A, a gate dielectric pattern GI may beinterposed between the gate electrode GE and the interfacial layer IL.Spacer structures GS may be disposed on opposite side surfaces of thegate electrodes GE, respectively. A capping structure GP may be disposedon the gate electrode GE. The spacer structures GS may each includefirst through third spacers SP1, SP2 and SP3. The capping structure GPmay include a first capping pattern CP1 and a second capping pattern CP2that are sequentially stacked. The gate electrodes GE, the gatedielectric pattern GI, the spacer structures GS and the capping patternGP may be similar to those described with reference to FIGS. 1 and 2.

Referring again to FIGS. 3 and 4A through 4C, the first and secondactive patterns AP1 and AP2 may include source/drain regions SD andchannel regions CH that are respectively positioned at upper portions ofthe first and second active patterns AP1 and AP2. Specifically, thesource/drain regions SD may be disposed at opposite sides of the gateelectrodes GE. As an example, the source/drain regions SD of the firstactive pattern AP1 may have a p-type conductivity, and the source/drainregions SD of the second active pattern AP2 may have an n-typeconductivity.

The channel region CH may be disposed between respective ones of thesource/drain regions SD. The channel region CH may be verticallyjuxtaposed with the gate electrodes GE. Although the gate electrode GEas shown in FIG. 1 covers a top surface of the channel region CH, eachof the gate electrodes GE according to the example of the inventiveconcept may cover the top surface and sidewalls of the channel regionCH.

The source/drain regions SD may include epitaxial patterns that aregrown using the first and second active patterns AP1 and AP2 under thesource/drain regions SD as a seed. In this case, the source/drainregions SD of the first active pattern AP1 may include a materialapplying a compressive strain to the channel region CH. The source/drainregions SD of the second active pattern AP2 may include a materialapplying a tensile strain to the channel region CH. For example, in thecase in which the substrate 100 is a silicon substrate, the source/drainregions SD of the first active pattern AP1 may include SiGe, of which alattice constant is greater than that of Si. The source/drain regions SDof the second active pattern AP2 may include SiC, of which a latticeconstant is smaller than that of Si, or may include Si, of which alattice constant is substantially equal to that of the substrate 100.When viewed in cross section, referring to FIG. 4C, the source/drainregions SD of the first active pattern AP1 may have a shape differentfrom the source/drain regions SD of the second active pattern AP2. Thismay be because the source/drain regions SD of the first active patternAP1 and the source/drain regions SD of the second active pattern AP2 areepitaxially grown using different substances.

A first interlayer insulating layer 130 may be disposed on the substrate100 and fill gaps between the gate electrodes GE. A top surface of thefirst interlayer insulating layer 130 may be coplanar with top surfacesof the capping structures GP. A second interlayer insulating layer 140may be disposed on the first insulating layer 130. The first and secondinterlayer insulating layers 130 and 140 may include a silicon oxidelayer.

Active contacts CA that are electrically connected to at least one ofthe source/drain regions SD may be provided. The active contacts CA maypass through the second interlayer insulating layer 140 and the firstinterlayer insulating layer 130 and be electrically connected to thesource/drain region SD. The active contacts CA may be disposed at a sideor opposite sides of at least one of the gate electrodes GE. The activecontacts CA may each include a conductive structure 185 and a barrierpattern 180 surrounding the conductive structure 185. The barrierpattern 180 may include a barrier conductive layer including, forexample, at least one of titanium nitride, tungsten nitride and tantalumnitride. The conductive structure 185 may include a metal layerincluding, for example, at least one of tungsten, titanium and tantalum.

The capping structure GP being in contact with the active contact CAwill be described in more detail with reference to FIGS. 4A and 5. In anexample of the inventive concept, the active contact CA may be aself-aligned contact (SAC). The active contact CA may be disposedbetween adjacent ones of the gate electrodes GE. The active contact CAmay contact the capping structure GP on at least one of the adjacentgate electrodes GE.

The capping structure GP contacting the active contact CA may be in astate in which a portion of the capping structure GP is removed incomparison with another capping structure GP not contacting the activecontact CA. Specifically, the capping pattern GP contacting the activecontact CA may be recessed. In other words, the second capping patternCP2 may have a sloped sidewall ER that contacts the active contact CA.

Since a portion of the second capping pattern CP2 is missing due to theactive contact CA, a width of the second capping pattern CP2 may vary inthe direction of its height. More specifically, the width of the secondcapping pattern CP2 may gradually decrease in a direction away from thesubstrate 100 (e.g., in a third direction D3). In other words, a lowerportion of the second capping pattern CP2 may be wider than an upperportion of the second capping pattern CP2 (in direction D2 in FIG. 4A).

An upper portion of the spacer structure GS that contacts the activecontact CA may be recessed due to the active contact CA. In thisrespect, the upper portion of the spacer structure GS may have a slopedsidewall ERa. The sloped sidewall ER of the second capping pattern CP2may extend directly from, i.e., be contiguous with, the sloped sidewallERa of the spacer structure GS to form a continuously sloped or curvedsidewall ER and ERa. The active contact CA may extend downwardly alongthe sloped sidewall ER and ERa and directly cover a sidewall of thespacer structure GS.

For example, the portion of the second capping pattern CP2 which laysatop the spacer structure GS may have a convex surface in contact withthe contact structure CA. The spacer structure GS (i.e, third spacerSP3) may also have a convex surface in contact with the contactstructure CA. The convex surface of the second capping pattern CP2 meetsthe convex surface of the spacer structure GS (i.e., the convex surfaceof the third spacer SP3) at a location adjacent to the contact structureCA. Adjacent to this location where the convex surfaces meet, the radiusof curvature of the convex surface of the second capping pattern CP2 maybe substantially the same as the radius of curvature of the convexsurface of the spacer structure GS (i.e., the radius of curvature of theconvex surface of the third spacer SP3). In other words, there may be asmooth transition of one surface to the other, i.e., there may besubstantially no inflection point at the location where the curved sidesurfaces of the second capping pattern CP2 and spacer structure GS meet.

While forming the active contact CA, the first through third spacersSP1, SP2 and SP3 may be protected by the second capping pattern CP2.Because the second spacer SP2 has a relatively low dielectric constant,a parasitic capacitance that may occur between the gate electrode GE andthe active contact CA may be reduced.

The second capping pattern CP2 may be vertically spaced apart from thegate electrode GE by the first capping pattern CP1 and the spacerstructure GS. Therefore, even if the second capping pattern CP2 has arelatively high dielectric constant, it may not affect parasiticcapacitance occurring between the gate electrode GE and the activecontact CA.

The capping structure GP of another example of a semiconductor deviceaccording to the inventive concept will now be described with referenceto FIGS. 4A, 6B and 6C.

As an example of the inventive concept, first, referring to FIGS. 4A and6B, an insulating pattern NO may be interposed between the first cappingpattern CP1 and the second capping pattern CP2. The insulating patternNO may include a native oxide formed on the first capping pattern CP1and the spacer structures GS. Thus, the insulating pattern NO maydirectly cover a top surface CP1 t of the first capping pattern CP1 andtop surfaces GSt of the spacer structure GS.

As an example, in the case in which the first capping pattern CP1include SiN, the insulating pattern NO may include a silicon oxide layer(i.e., native oxide layer) formed on the SiN layer. However, the nativeoxide layer is not limited to the silicon oxide layer. The material ofthe native oxide layer depends on materials from which the first cappingpattern CP1 and the spacer structures GS are formed. For example, in thecase in which the first capping pattern CP1 includes Al₂O₃, theinsulating pattern NO may include an aluminum oxide layer as the nativeoxide layer, formed on the Al₂O₃ layer.

As another example of the inventive concept, referring to FIGS. 4A and6C, the first capping pattern may have a substantially flat top surfaceCP1 t. In other words, unlike the first capping pattern CP1 and thesecond capping pattern CP2 as described with reference to FIGS. 1 and 2,the first capping pattern CP1 according to this example may not includean indentation DE and the second capping pattern CP2 may also notinclude a protrusion portion PP. The top surface CP1 t of the firstcapping pattern CP1 may be substantially coplanar with the top surfacesGSt of the spacer structures GS.

FIGS. 7, 9, 11, 13, 15, 17, 19, 21, 23 and 25 are plan viewsillustrating a method of manufacturing a semiconductor device accordingto an example of the inventive concept. FIGS. 8A, 10A, 12A, 14A, 16A,18A, 20A, 22A, 24A and 26A are cross-sectional views taken along linesA-A′ of FIGS. 7, 9, 11, 13, 15, 17, 19, 21, 23 and 25, respectively,FIGS. 8B, 10B, 12B, 14B, 16B, 18B, 20B, 22B, 24B and 26B arecross-sectional views taken along lines B-B′ of FIGS. 7, 9, 11, 13, 15,17, 19, 21, 23 and 25, respectively, and FIGS. 10C, 12C, 14C, 16C, 18C,20C, 22C, 24C and 26C are cross-sectional views taken along lines C-C′of FIGS. 9, 11, 13, 15, 17, 19, 21, 23 and 25, respectively.

Referring to FIGS. 7, 8A and 8B, a first active pattern AP1 and a secondactive pattern AP2 may be formed in a region of a substrate 100. Forexample, the substrate 100 may be a silicon substrate, a germaniumsubstrate or a silicon-on-insulator (SOI) substrate. In some examples,the region of the substrate 100 may be a memory cell region in which aplurality of memory cells for storing data are disposed. In otherexamples, the region of the substrate 100 may be a logic cell region inwhich a plurality of logic transistors for forming logic circuits aredisposed.

Specifically, first trenches TC1 that define the first active patternAP1 and the second active pattern AP2 may be formed by patterning anupper portion of the substrate 100. The first and second active patternsAP1 and AP2 may be spaced apart from each other in the first directionD1. The first and second active patterns AP1 and AP2 may have a linearshape that extends in the second direction D2. First device isolationpatterns ST1 may be formed to fill the first trenches T1. The firstdevice isolation patterns ST1 may be formed to expose upper portions ofthe first and second active patterns AP1 and AP2. In other words, theupper portions of the first and second active patterns AP1 and AP2 mayprotrude vertically (e.g., in the third direction D3) above the firstdevice isolation patterns ST1.

Next, the upper portion of the substrate may be patterned again to formsecond trenches TC2. At least one of the second trenches TC2 may beformed between the first active pattern AP1 and the second activepattern AP2. When forming the second trenches TC2, a portion of thefirst device isolation patterns ST1 may be removed. Bottom surfaces ofthe second trenches TC2 may be lower than those of the first trenchesTC1. Second device isolation patterns ST2 may be formed to fill thesecond trenches TC2.

As an example, the first and second device isolation patterns ST1 andST2 may together form a structure of substantially one integral orunitary layer of insulating material. The first and second deviceisolation patterns ST1 and ST2 may be formed of silicon oxide.

Referring to FIGS. 9, 10A through 10C, sacrificial gate patterns 110 andgate mask patterns 115 on the respective sacrificial gate mask patterns115 may be formed on the substrate 100. The sacrificial gate patterns110 may be formed to cross the first and second active patterns AP1 andAP2 and extend in the first direction D1. The sacrificial gate patterns110 may cover top surfaces and sidewalls of the first and second activepatterns AP1 and AP2. In addition, the sacrificial gate patterns 110 maycover a portion of top surfaces of the first and second device isolationpatterns ST1 and ST2.

The forming of the sacrificial gate patterns 110 and the gate maskpatterns 115 may include sequentially forming a sacrificial gate layerand a gate mask layer on the substrate 100 to cover he first and secondpatterns AP1 and AP2 and sequentially patterning the sacrificial gatelayer and the gate mask layer. The sacrificial gate layer may includepoly-silicon. The gate mask layer may include silicon nitride or siliconoxynitride.

Referring to FIGS. 11 and 12A through 12B, a pair of spacer structuresGS may be formed to cover opposite sidewalls of each of the sacrificialgate patterns 110. Source/drain regions SD may be formed on the upperportions of the first and second active patterns AP1 and AP2. Thesource/drain regions SD may be positioned at opposite sides of eachsacrificial gate pattern 110. Channel regions CH may each be disposedbetween respective ones of the source/drain regions SD.

Specifically, the forming of the spacer structures GS may includeforming a gate spacer layer on the substrate 100 to conformally coverthe sacrificial gate patterns 110 and the gate mask patterns 115 andanisotropically etching the gate spacer layer. The gate spacer layer maybe formed by a chemical vapor deposition (CVD) process or an atomiclayer deposition (ALD) process. The gate spacer layer may includemultiple layers that are sequentially stacked, i.e., may be amulti-layered structure. In this respect, the gate spacer layer may beformed of at least one of SiO₂, SiCN, SiCON and SiN.

The resulting spacer structure GS may include a first spacer SP1, asecond spacer SP2 and a third spacer SP3 (refer to FIG. 6A). In thiscase, the second spacer SP2 may be formed of a material having a lowerdielectric constant than materials of the first and third spacers SP1and SP3. In some examples, the third spacer SP3 may be formed after thefirst and second spacers SP1 and SP2 and the source/drain regions SD areformed. In other examples, the first through third spacers SP1, SP2 andSP3 may be concurrently formed.

Specifically, the forming of the source/drain regions SD may includeremoving upper portions of the first and second active patterns AP1 andAP2 at opposite sides of the respective sacrificial gate patterns 110and performing a selective epitaxial growing process using portions ofthe first and second active patterns AP1 and AP2 exposed by the removal,as a seed. The removal of upper portions of the first and second activepatterns AP1 and AP2 may be performed by a wet etching process using thegate mask patterns 115 and the spacer structures GS as an etching mask.

The source/drain regions SD of the first active pattern AP1 may beformed to apply a compressive strain to the channel region CHtherebetween. As an example, in the case in which the substrate 100 is asilicon substrate, the source/drain regions SD of the first activepattern AP1 may be formed of SiGe. The source/drain regions SD of thefirst active pattern AP1 may be doped with p-type impurities after theepitaxial growing process or during the epitaxial growing process.

The source/drain regions SD of the second active pattern AP2 may beformed to apply a tensile strain to the channel region CH therebetween.As an example, in the case in which the substrate 100 is a siliconsubstrate, the source/drain regions SD of the second active pattern AP2may be formed of SiC or Si. The source/drain regions SD of the secondactive pattern AP2 may be doped with n-type impurities after theepitaxial growing process or during the epitaxial growing process.

In some examples, because the source/drain regions SD of the firstactive pattern AP1 and the source/drain regions SD of the second activepattern AP2 are epitaxially grown using different materials from eachother, the source/drain regions SD of the first active pattern AP1 andthe source/drain regions SD of the second active pattern AP2 may beformed to have different sizes and different shapes from each other.

Referring to FIGS. 13 and 14A through 14C, a first interlayer insulatinglayer 130 may be formed on the substrate 100. For example, the firstinterlayer insulating layer 130 may be formed of silicon oxide. Aplanarization process may be performed on the first interlayerinsulating layer 130 until top surfaces of the sacrificial gate patterns110 are exposed. The planarization process may include an etch-backprocess and/or a chemical mechanical polishing (CMP) process. Whenplanarizing the first interlayer insulating layer 130, the gate maskpatterns 115 may be removed together to expose the sacrificial gatepatterns 110.

The exposed sacrificial gate patterns 110 may be removed such that gatetrenches GT may be formed to each expose the channel region CH betweenadjacent ones of spacer structures GS. The gate trenches GT may beformed by performing an etching process of selectively removing portionsof the sacrificial gate patterns 110.

Referring to FIGS. 15 and 16A through 16C, an oxidation process may beperformed on the exposed channel regions CH using plasma such thatinterfacial layers IL may be respectively grown from the channel regionsCH. The interfacial layers IL may be results of a thermal oxidationand/or a chemical oxidation of the channel regions CH. The oxidationprocess may be conducted using an oxidizing agent, for example, at leastone of oxygen (O₂), ozone (O₃) and water vapor (H₂O). The interfaciallayers IL may include a silicon oxide layer.

A gate dielectric pattern GI and a gate electrode GE may be sequentiallyformed in each of the gate trenches GT to fill each of the gate trenchesGT. Specifically, a gate dielectric layer may be formed in the gatetrenches GT to fill a portion of each of the gate trenches GT. The gatedielectric layer may be formed to cover the top surfaces and sidewallsof the channel regions CH. As an example, the gate dielectric layer mayinclude at least one of silicon oxide, silicon oxynitride and a high-kdielectric material of which a dielectric constant is higher than thatof silicon oxide.

A gate conductive layer may be formed on the gate dielectric layer tofill remaining portions of the gate trenches GT. For example, the gateconductive layer may include at least one of a doped semiconductormaterial, a conductive metal nitride and a metal. The sequentiallystacked gate dielectric layer and gate conductive layer may beplanarized such that the gate dielectric patterns GI and the gateelectrode GE may be formed in each gate trench GT.

The gate electrodes GE may be recessed such that first recess regionsRC1 may be defined on the respective gate electrodes GE. In other words,top surfaces of the gate electrodes GE may be lower than top surfaces ofthe spacer structures GS and top surfaces of the gate dielectricpatterns GI. Each of the first recess regions RC1 may have a recessdefined by inner sidewalls of the gate dielectric pattern GI and the topsurface of the gate electrode GE. The recessing of the gate electrode GEmay include selectively etching the gate electrodes GE to remove aportion thereof.

Referring to FIGS. 17 and 18A through 18C, a first capping layer 150 maybe formed on the first interlayer insulating 130. The first cappinglayer 150 may fill the recesses of first recess regions RC1. Due to thefirst recess regions RC1, depressed regions DEa may be formed in a topsurface of the first capping layer 150. The first capping layer 150 maybe formed of at least one of SiON, SiCN, SiCON, SiN and Al₂O₃.

Referring to FIGS. 19 and 20A through 20C, the first capping layer 150may be etched to form first capping patterns CP1 on the gate electrodesGE. The first capping patterns CP1 may respectively fill the recesses offirst recess regions RC1.

The first capping layer 150 may be etched such that top surfaces of thefirst capping patterns CP1 are lower than a top surface of the firstinterlayer insulating layer 130. When etching the first capping layer150, the spacer structures GS and the gate dielectric patterns GI may beetched together. Therefore, the top surfaces of the spacer structures GSand the top surfaces of the gate dielectric patterns GI may be lowerthan the top surface of the first interlayer insulating layer 130. As anexample, a portion of the top surface of the first capping pattern CP1may be substantially coplanar with the top surfaces of the spacerstructures GS.

Due to the depressed regions DEa formed in the top surface of the firstcapping layer 150, indentations DE may be respectively formed in the topsurfaces of the first capping patterns CP1. The indentations DE may beformed due to an anisotropic dry etching of the first capping layer 150to form the first capping patterns CP1.

In some examples, in the case in which the etching process is performedafter planarizing the first capping layer 150, the depressed regions DEain the top surface of the first capping layer 150 may be removed. Inthis case, the first capping patterns CP1 may have substantially flattop surfaces without the indentations DE (refer to FIG. 6C).

By performing the etching process, the top surfaces of the spacerstructures GS, the top surfaces of the gate dielectric patterns GI andthe top surfaces of the first capping patterns CP1 may be lower than thetop surface of the first interlayer insulating layer 130 such thatsecond recess regions RC2 may be formed. The recesses of the secondrecess regions RC2 may each expose the top surfaces of the pair ofspacer structures GS, the top surface of the gate dielectric pattern GIand the top surface of the first capping pattern CP1.

In some examples, an insulating pattern NO may be formed on the exposedtop surfaces of the spacer structures GS, the exposed top surface of thegate dielectric pattern G1 and the exposed top surface of the firstcapping pattern CP1. The insulating pattern NO may include a nativeoxide that is formed naturally by contact of the exposed layers with anair (refer to FIG. 6B).

Referring to FIGS. 21 and 22A through 22C, a second capping layer 160may be formed on the first interlayer insulating layer 130. The secondcapping layer 160 may fill the second recess regions RC2. The secondcapping layer 160 may be formed of a material having an etchingselectivity with respect to the first interlayer insulating layer 130.The second capping layer may be formed of, for example, at least one ofSiON, SiCN, SiCON, SiN and Al2O₃. In some examples, the second cappinglayer 160 may be formed of the same material as the first cappingpatterns CP1. In other examples, the second capping layer 160 may beformed of a material different from a material of the first cappingpatterns CP1. In this case, a dielectric constant of the second cappinglayer 160 may be greater than that of the first capping patterns CP1.

Referring to FIGS. 23 and 24A through 24C, a planarizing process of thesecond capping layer 160 may be performed until the top surface of thefirst interlayer insulating layer 130 is exposed. Thus, second cappingpatterns CP2 may be formed in the respective recesses of the secondrecess regions RC2. The planarization process may include an etch-backprocess and/or a CMP process. The first capping pattern CP1 and thesecond capping pattern CP2 may form a capping structure GP. The secondcapping pattern CP2 may be formed to completely cover the top surface ofthe first capping pattern CP1 and the top surfaces of the pair of spacerstructures GS. In other words, the second capping pattern CP2 may beformed to have a greater width than the first capping pattern CP1. Thesecond capping pattern CP2 may be spaced apart from the gate electrodeGE with the first capping pattern CP1 therebetween.

Referring to FIGS. 25 and 26A through 26C, a second interlayerinsulating layer 140 may be formed on the first interlayer insulatinglayer 130, The second interlayer insulating layer 140 may be formed of,for example, silicon oxide.

Contact holes CAH may be formed at a side or opposite sides of at leastone of the gate electrodes GE. Specifically, a photoresist pattern PRmay be formed on the second interlayer insulating layer 140. Thephotoresist pattern PR may include openings defining positions of thecontact holes CAH. The openings may each be vertically juxtaposed oraligned with the source/drain region SD. The openings may each be formedto have an area, as viewed in plan, larger than that of the source/drainregion SD. The first and second interlayer insulating layers 130 and 140may be etched using the photoresist patterns PR as an etch mask to formthe contact holes CAH exposing the source/drain regions SD.

The etching process for forming the contact holes CAH may include a dryetching process capable of selectively etching the first and secondsource/drain regions SD. For example, the etching process may beperformed using fluorocarbon (C_(x)F_(y)) as an etching gas

The openings of the photoresist pattern PR may each be formed to have awidth greater than a distance between the adjacent gate electrodes GE(refer to FIG. 26A). While performing the etching process, a portion ofthe capping structure GP and a portion of the space structure GS may beetched, while the other portions of the capping structure GP and thespace structure GS remain intact. Therefore, the contact holes CAH mayselectively expose the source/drain region SD without exposing the gateelectrodes GE adjacent thereto. That is, the contact holes CAH may beformed in a self-aligned manner. As a portion of the capping structureGP is etched, the capping structure GP may have a sloped sidewall ER.

The spacer structure GS may include a low-k dielectric material (e.g.,the material of the second spacer SP2) so as to reduce a parasiticcapacitance between the gate electrode GE and an active contact CAdescribed later. However, an etch resistance of the spacer structure GSdue to the low-k dielectric material may be relatively low and thus, thespacer structure GS may be easily etched during the etching process forforming the contact holes CAH.

Because the second capping pattern CP2 is formed to completely cover thetop surface of the spacer structure GS, the spacer structure GS may beeffectively protected during the etching process for forming the contactholes CAH. For example, the second capping pattern CP2 may be formed ofa high-k dielectric material (e.g., AL₂O₃) having a high etchingselectivity with respect to the silicon oxide layer. Thus, the etchresistance of the second capping pattern CP2 with respect to the etchingprocess may be relatively high. The second capping pattern CP2 is spacedapart from the gate structure GE by the first capping pattern CP1 andthe spacer structure GS, and thus the second capping pattern CP2 havingthe high-k dielectric material may not affect the parasitic capacitance.In some examples, the second capping pattern CP2 may have the samematerial (e.g., SiN) as the first capping pattern CP1. However, becausethe second capping pattern CP2 has a larger volume than the firstcapping pattern CP1, the etch resistance of the second capping patternCP2 may be relatively high by virtue of its physical structure.

Referring again to FIGS. 3 and 4A through 4C, the active contacts CA maybe formed to fill the contact holes CAH. The active contacts CA may eachinclude a barrier pattern 180 and a conductive structure 185. Thebarrier pattern 180 may include a barrier conductive layer formed of,for example, at least one of titanium nitride, tungsten nitride andtantalum nitride. The conductive structure 185 may include a metal layerformed of, for example, at least one of tungsten, titanium and tantalum.

Although not shown, through a subsequent process, interconnection layersmay be formed on the second interlayer insulating layer 140 to contactthe active contacts CA. The interconnection layers may include aconductive material.

FIG. 27 is a plan view illustrating a semiconductor device according toan example of the inventive concept. FIGS. 28A and 28B arecross-sectional views taken along lines A-A′ and B-B′ of FIG. 27,respectively. Hereinafter, the same elements as described with referenceto FIGS. 3, 4A through 4C and 6A through 6C will not be described againor will be mentioned only briefly for the sake of brevity.

Referring to FIGS. 27 and 28A and 28B, a first transistor TR1 and asecond transistor may be disposed on a substrate 100. A first activepattern AP1 and a second active pattern AP2 may be disposed on thesubstrate 100. The first active pattern AP1 and the second activepattern AP2 may be active regions for the first transistor TR1 and thesecond transistor TR2, respectively.

Gate electrodes GE may be disposed on the first and second activepatterns AP1 and AP2 to cross the first and second active patterns AP1and AP2. A gate dielectric pattern GI may extend along sidewalls and abottom surface of each of the gate electrodes GE. Spacer structures GSmay be spaced apart from each of the gate electrodes GE with the gatedielectric pattern GI interposed therebetween. A capping structure GPmay be disposed on each of the gate electrodes GE. A top surface of thegate dielectric pattern GI and a top surface of each of the gateelectrodes GE may contact a bottom surface of the capping structure GP.The gate electrodes GE, the gate dielectric pattern GI, the spacerstructure GS and the capping structure GP may be similar to thosedescribed with reference to FIGS. 3, 4A through 4C, 5 and 6A through 6C.

The first and second active patterns AP1 and AP2 may each includesource/drain regions SD and a channel regions CH. The channel regions CHmay each include a plurality of semiconductor patterns NS which arevertically stacked. The semiconductor patterns NS may be spaced apartfrom each other in the third direction D3. The source/drain regions SDmay directly contact sidewalls of the semiconductor patterns NS. Inother words, the semiconductor patterns NS may connect the source/drainregions on opposite sides thereof. Referring again to FIG. 28A, althoughthree semiconductor patterns NS are illustrated, the inventive conceptis not particularly limited to any particular number of thesemiconductor patterns NS. In some examples, the semiconductor patternsNS may include, for example, at least one of Si, SiGe and Ge. Thesemiconductor patterns NS may have an equal thickness to each other, butthe inventive concept is not limited thereto.

As described above, the gate electrode GE and the gate dielectricpattern GI may cover the channel region CH and may extend in the firstdirection D1. More specifically, the gate electrode GE and the gatedielectric pattern GI may fill spaces between the semiconductor patternsNS. In this example, the gate dielectric pattern GI may contact thesemiconductor patterns NS. The gate electrode GE may be spaced apartfrom the semiconductor patterns NS with the gate dielectric pattern GIinterposed therebetween.

The first and second transistors TR1 and TR2 as described with referenceto FIGS. 3 and 4A through 4C may each be a tri-gate-type field effecttransistor (i.e., a FinFET). The gate electrode GE may surround an outerperipheral surface of each semiconductor pattern NS. The first andsecond transistors TR1 and TR2 may each be a gate-all-around-type fieldeffect transistor that includes the channel regions CH, each of whoseouter peripheral surfaces is surrounded by the gate electrode GE.

Barrier insulating patterns BP may be provided between the source/drainregions SD and the gate electrode GE. The barrier insulating patterns BPmay be spaced apart from each other with semiconductor patterns NStherebetween. The barrier insulating patterns BP may contact the gatedielectric pattern GI. The barrier insulating patterns BP may include atleast one of silicon oxide, silicon nitride and silicon oxynitride.

The source/drain regions SD may include epitaxial patterns formed usingthe semiconductor patterns NS and the substrate 100 as a seed. In thecase in which the first transistor TR1 is a PMOSFET, the source/drainregions SD of the first active pattern AP1 may include a semiconductormaterial applying a compressive strain to the channel region CH. In thecase in which the second transistor TR2 is an NMOSFET, the source/drainregions SD of the second active pattern AP2 may include a semiconductormaterial applying a tensile strain to the channel region CH.

First and second interlayer insulating layers 130 and 140 may bedisposed on the substrate 100 to cover the gate electrodes GE. Activecontacts CA may be formed to penetrate the first and second interlayerinsulating layers 130 and 140 and be electrically connected to thesource/drain regions SD. At least one of the active contacts CA may be aself-aligned contact. The active contact CA may contact the cappingstructure GP. The capping structure GP may have a sloped sidewall ERcontacting the active contact CA

FIG. 29 is a plan view illustrating a semiconductor device according toan example of the inventive concept. FIGS. 30A and 30B arecross-sectional views taken along lines A-A′ and B-B′ of FIG. 29,respectively. Hereinafter, the same elements as described with referenceto FIGS. 1 and 2 will not be described again or will mentioned onlybriefly for the sake of brevity.

Referring to FIGS. 29, 30A and 30B, device isolation patterns STdefining active patterns AP may be provided on a substrate 100. Thedevice isolation patterns ST may include, for example, a silicon oxidelayer. In a plan view, the active patterns AP may each be elongated(“bar-shaped”) with its major axis oriented in a third direction D3. Thethird direction D3 may cross a first direction D1 and a second directionD2 that cross each other. The first, second and third directions D1, D2and D3 may each be a direction parallel to a top surface of thesubstrate 100. A fourth direction D4 may be a direction perpendicular tothe top surface of the substrate 100 and the first, second and thirddirections D1, D2 and D3.

Gate lines GL may be disposed in the substrate 100 to cross the activepatterns AP. The gate lines GL may extend in the second direction D2 andbe spaced along the first direction D1. The gate lines GL may be buriedwithin the substrate 100. The gate lines GL may include a conductivematerial, for example, at least one of a doped semiconductor material(e.g., a doped silicon, a doped germanium), a conductive metal nitride(e.g., titanium nitride, tantalum nitride), a metal (e.g., tungsten,titanium, tantalum) and a metal-semiconductor compound (e.g., tungstensilicide, cobalt silicide, titanium silicide).

Gate dielectric patterns 104 may be interposed between the gate lines GLand the active patterns AP and between the gate lines GL and the deviceisolation patterns ST. The gate dielectric patterns 104 may include, forexample, a silicon oxide layer, a silicon nitride layer and/or a siliconoxynitride layer.

Mask patterns 108 may be respectively provided on top surfaces of thegate lines GL. The top surfaces of the gate lines GL may besubstantially coplanar with the top surface of the substrate 100. Themask pattern 108 may include, for example, a silicon oxide layer, asilicon nitride layer and/or a silicon oxynitride layer.

A first impurity region SD1 and second impurity regions SD2 spaced apartfrom each other with the first impurity region SD1 interposedtherebetween may be provided in each active pattern AP. The firstimpurity region SD1 may be disposed in the active pattern AP betweenadjacent ones of a respective pair of the gate lines GL. The secondimpurity regions SD2 may be respectively disposed in the active patternAP at opposite sides of the pair of the gate lines GL. That is, thesecond impurity regions SD2 may be spaced apart from each other with thepair of the gate lines GL therebetween. The first impurity region SD1may extend deeper than the second impurity regions SD2 into the activepattern AP. The first impurity region SD1 may include impurities of thesame conductivity type as the second impurity regions SD2.

Conductive patterns may be disposed to cross the first impurity regionSD1 of first active patterns AP. The conductive patterns may include bitlines BL. The bit lines BL may extend in the first direction D1 and bearranged in the second direction D2. The bit lines BL may beelectrically connected to the first impurity regions SD1. As an example,the bit lines BL may include, for example, at least one of a dopedsemiconductor material, a conductive metal nitride and a metal.

Spacer structures GS may be respectively disposed on opposite sidewallsof each bit line BL. A capping structure may be disposed on each bitline. In some examples, the bit line BL, the spacer structure GS and thecapping structure GP may be similar to the gate electrode GE, the spacerstructure GS and the capping structure GP as described with reference toFIGS. 1 and 2.

A first interlayer insulating layer 130 and a second interlayerinsulating layer 140 may be provided on the substrate 100. Activecontacts CA may extend through the first and second interlayer layers130 and 140 and be electrically connected to the second impurity regionsSD2. At least one active contact CA may be a self-aligned contact. Theactive contact CA may contact the capping structure GP and have a slopedsidewall ER contacting the active contact CA.

Landing pads LP may be disposed on the second interlayer insulatinglayer 140 to be electrically connected to the active contacts CA,respectively. The landing pads LP may be arranged in two-dimensions. Thelanding pads LP may overlap the active contacts CA. The landing pads LPmay include a conductive material, for example, a doped semiconductormaterial, a metal and/or a meal-semiconductor compound. Third interlayerinsulating layer 145 may fill gaps between the landing pads LP.

Data storage elements DS may be disposed on the third interlayerinsulating layer 145 as electrically connected to the landing pads LP,respectively. The data storage elements DS may be memory elementscapable of storing data. In this case, the field effect transistorsincluding the active patterns AP and the gate lines GL may function asswitching elements. In some examples, the data storage elements DS mayeach be a memory element having a capacitor, a magnetic tunnel junction(MTJ) pattern, or a variable-resistance structure including aphase-change material for storing data.

In the semiconductor device according to the present inventive concept,the conductive pattern can be protected effectively while forming theself-aligned contact and the parasitic capacitance between the contactand the conductive pattern can also be reduced. Accordingly, it ispossible to improve an operation speed of the semiconductor device.

Although the present inventive concept has been particularly shown anddescribed with reference to examples thereof, it will be understood bythose of ordinary skill in the art that various changes in form anddetails may be made to such examples without departing from the spiritand scope of the inventive concept as defined by the following claims.

What is claimed is:
 1. A semiconductor device, comprising: a substratehaving an active pattern; a conductive pattern crossing the activepattern, the conductive pattern having opposite side surfaces; spacerstructures each disposed on a respective one of the opposite sidesurfaces of the conductive pattern, the spacer structures having topsurfaces, respectively; and a capping structure on the conductivepattern, wherein the capping structure includes a first capping patternhaving a top surface, and a second capping pattern, the first cappingpattern is interposed between the spacer structures, the second cappingpattern is disposed on the top surface of the first capping pattern, andthe second capping pattern extends, in a direction parallel to an uppersurface of the substrate, beyond the opposite side surfaces of theconductive pattern and onto the top surfaces of the spacer structuresbut not beyond either of the spacer structures in said direction, and amaximum width of the second capping pattern as taken between oppositeside surfaces thereof is greater than a maximum width of the firstcapping pattern as taken between opposite side surfaces thereof.
 2. Thedevice according to claim 1, wherein the top surfaces of the spacerstructures are higher than a top surface of the conductive pattern. 3.The device according to claim 1, wherein the first capping patternincludes an indentation in a top surface thereof.
 4. The deviceaccording to claim 1, wherein the capping structure further includes aninsulating pattern including an oxide layer between the first cappingpattern and the second capping pattern.
 5. The device according to claim1, wherein the top surface of the first capping pattern is substantiallycoplanar with the top surfaces of the spacer structures.
 6. The deviceaccording to claim 1, wherein each of the spacer structures include afirst spacer, a second spacer and a third spacer, the second spacer isinterposed between the first spacer and the third spacer, and adielectric constant of the second spacer is lower than a dielectricconstant of each of the first and third spacers.
 7. The device accordingto claim 6, wherein a width of the second spacer, in a directionperpendicular to the opposite side surfaces of the conductive pattern,is greater than a width of each of the first and third spacers in thedirection perpendicular to the opposite side surfaces of the conductivepattern.
 8. The device according to claim 1, further comprising: aninterlayer insulating layer covering the capping structure; and anactive contact extending through the interlayer insulating layer,wherein the second capping pattern has a side surface, inclined relativeto a vertical direction perpendicular to an upper surface of thesubstrate, contacting the active contact, and the second capping patternhas a width, in a direction parallel to the upper surface of thesubstrate that decreases away from the upper surface of the substratealong the vertical direction.
 9. The device according to claim 1,wherein the active pattern includes a channel region having a top andopposite sides, and the conductive pattern covers the top and oppositesides of the channel region.
 10. The device according to claim 1,wherein the active pattern includes a channel region, the channel regionincludes semiconductor patterns that are vertically spaced apart fromeach other, and the conductive pattern surrounds the semiconductorpatterns.
 11. The device according to claim 1, further comprising: aninterlayer insulating layer disposed on the substrate above a region ofthe active pattern of the substrate and having a bottom surfaceextending on a top surface of the second capping pattern; and a contactstructure extending vertically from said region of the active patternand through the interlayer insulating layer, wherein the interlayerinsulating layer comprises an oxide, the contact structure comprises atleast one electrically conductive member, the contact structure isdisposed against the second capping pattern and at least one of thespacer structures, and the second capping pattern is of SiN or Al₂O₃.12. A semiconductor device, comprising: a substrate having an activepattern; a conductive pattern crossing the active pattern; a spacerstructure on each of at least one of opposite sides surfaces of theconductive pattern; a capping structure on the conductive pattern, thecapping structure including a first capping pattern and a second cappingpattern on the first capping pattern, the second capping pattern havinga top surface, a side surface and a bottom portion; an interlayerinsulating layer disposed on the substrate above the capping structureand above a region of the active pattern of the substrate; and an activecontact extending upwardly from said region of the active pattern of thesubstrate, wherein the spacer structure has an outer side surface facingaway from the conductive pattern, the first capping pattern has oppositeside surfaces, and a top portion having an indentation, the secondcapping pattern has a top surface, a first side surface, a second sidesurface and a bottom portion, the bottom portion of the second cappingpattern comprises a protrusion received in the indentation as engagedwith the first capping pattern, a maximum width of the second cappingpattern as taken between the first side surface and the second sidesurface thereof is greater than a maximum width of the first cappingpattern as taken between the opposite side surfaces thereof, the firstside surface of the second capping pattern meets the outer side surfaceof the spacer structure, the interlayer insulating layer has a bottomsurface covering the top surface of the second capping pattern of thecapping structure, and the active contact extends through the interlayerinsulating layer.
 13. The device according to claim 12, wherein thecapping structure further includes an insulating pattern between thefirst capping pattern and the second capping pattern, and the insulatingpattern includes an oxide.
 14. The device according to claim 12, whereinthe spacer structure has a top surface higher than a top surface of theconductive pattern.
 15. The device according to claim 12, wherein thebottom portion of the second capping pattern has a width that is greaterthan that of an upper portion of the second capping pattern.
 16. Thedevice according to claim 12, wherein the spacer structure has a topsurface, the top surface of the second capping pattern is a flat surfaceparallel with the bottom surface of the interlayer insulating layer, thebottom portion of the second capping pattern has a flat surface parallelto the top surface of the second capping pattern and lying over the topsurface of the spacer structure, and the protrusion protrudes downwardlytowards the first capping pattern from the flat surface of the bottomportion.
 17. A semiconductor device, comprising: a substrate having anactive pattern including a source/drain (S/D) region; an interlayerdielectric layer on the substrate; at least one conductive patternextending longitudinally in a first direction across the active patternwithin the interlayer dielectric layer, the conductive pattern havingopposite side surfaces; spacer structures on the opposite side surfacesof the conductive pattern, respectively, the spacer structures havingrespective top surfaces; a gate dielectric pattern interposed betweenthe active pattern and the conductive pattern, the gate dielectricpattern having a pair of extension portions extending vertically betweenthe spacer structures and the conductive pattern, the extension portionshaving inner side surfaces facing toward each other and respective topsurfaces coplanar with the top surfaces of the spacer structures; acapping structure on the conductive pattern; and a contact structureextending vertically in the interlayer dielectric layer to the S/Dregion, the contact structure comprising a conductive memberelectrically connected to the S/D region, wherein the capping structureincludes: a first capping pattern interposed in its entirety between theextension portions of the gate dielectric pattern, the first cappingpattern having opposite side surfaces contacting the inner sidessurfaces of the extension portions, respectively, and an uppermostsurface disposed no higher than the extension portions; and a secondcapping pattern having a first portion disposed on a top surface of thefirst capping pattern, and a second portion covering top surfaces of theextension portions and the top surfaces of the spacer structures,respectively, the second portion of the second capping pattern directlycontacting the top surfaces of the extension portions, the contactstructure is disposed against one of the spacer structures and thesecond portion of the second capping pattern, and the second cappingpattern is of material having an etch selectivity with respect to thatof the interlayer dielectric layer.
 18. The device according to claim17, wherein the interlayer dielectric layer includes an oxide, and thesecond capping pattern is of SiN or Al₂O₃.
 19. The device according toclaim 17, wherein each of the spacer structures includes a first spacer,a second spacer and a third spacer, the second spacer is of materialwhose composition includes oxygen and is interposed between the firstspacer and the third spacer, and the second spacer has a dielectricconstant lower than that of each of the first and third spacers.
 20. Thedevice according to claim 17, wherein the second portion of the secondcapping pattern has a convex surface in contact with the contactstructure, one of the spacer structures has a convex surface in contactwith the contact structure, the convex surface of the second cappingpattern meets the convex surface of said one of the spacer structures ata location adjacent to the contact structure, and a radius of curvatureof the convex surface of the second capping pattern adjacent to thelocation is substantially the same as that of convex surface of said oneof the spacer structures.